Dave Mehlman, the director of The Nature Conservancy’s migratory bird program, is blogging all week about the new “State of the Birds 2010″ report, of which he is a co-author. Read all his posts on the report — then go to my.nature.org to learn more about the report and the Conservancy’s work to protect birds.
There is an almost irresistible tendency when discussing the effects of climate change on birds (as illustrated by the State of the Birds report) to portray the results as inevitably bad. Indeed, our analyses of bird species vulnerability to climate change does suggest that many species show elevated vulnerability to climate change.
However, the great difference between birds from different habitat types in their vulnerability suggests that there are indeed some species who will do just fine in the face of climate change, including some who may well prosper. In addition, some conservation efforts are already underway to help birds adapt to a changing climate, providing yet another element of good news.
The relatively low proportion of bird species occurring in forests suggests that, due to their high reproductive potential and large ranges, many forest birds will fare better in the future (though we may see some species that become rarer in the United States but more common in Canada).
There are numerous examples of birds that are now of relatively restricted range in the United States but are currently expanding dramatically, such as Cactus Wren, Cave Swallow and White-winged Dove. Similarly, species now rare in United States but found commonly in Mexico may move northward and become more common in our country, including Northern Beardless-Tyrannulet, Bronzed Cowbird and Crested Caracara.
Perhaps the best news is that conservation efforts are already underway that will help birds in the face of climate change. For instance:
- Planners and refuge designers across the country are aware of the changes that are coming and can incorporate this knowledge into their work — for example, by developing altitudinal or elevational corridors connecting protected areas.
- Recent efforts at translocating individuals from one place to another, such as those implemented for the Bermuda Petrel, offer great hope for ensuring the survival of rare species, albeit in a relatively expensive manner.
- The Nature Conservancy has been actively partnering with the U.S. Fish and Wildlife Service at the Alligator River National Wildlife Refuge, North Carolina, in an innovative project to protect coastal marshes by plugging ditches to limit saltwater intrusion, planting salt tolerant species, and building oyster reefs for shoreline protection.
Climate change presents a strong challenge to most of our nation’s birds, exacerbating the largely negative trends we showed in the 2009 State of the Birds report. However, not all species will be affected equally –and some perhaps many species will benefit in some form. There are promising strategies for helping species adapt to a changing climate and these efforts must be expanded, coupled with a rigorous monitoring scheme to determine their effectiveness. Although the picture appears dark for birds overall regarding climate change, there are some lights in the darkness which may help guide our way.
(Image: Cactus wren. Image credit: SearchNetMedia/Flickr through a Creative Commons license.)